Roberts' rep tells ET that "it will be quite a while before she regains her strength," but shares that many of her GMA friends have already gone to visit her.

"This journey is as much about the mind as it is the body," the 51-year-old said in a video message. "Thoughts are so powerful. You've got to change the way you think in order to change the way you feel. And let me just say this lastly, I feel the love and I thank you for it. Thank you."

Roberts, who just completed eight days of chemotherapy, had the transplant to treat a rare blood disorder, myelodysplastic syndrome.